Brain function can experience impairment of a temporary or permanent nature as a result of various different brain injuries. Such brain injuries can include stroke, where blood flow to the brain is temporarily blocked. Also, head trauma can cause brain injury. Other sources of brain injury can include heat stroke, where an excessively high temperature is experienced by the brain, aneurysms, and other bleeding disorders, as well as other deleterious brain injury phenomena.
One common feature in treating and successfully recovering from brain injury is the concept that time is critical in treating brain injury. In particular, when brain cells die, the associated function provided by those brain cells is more apt to be lost by the patient. When a sufficient number of brain cells have died, such function is lost, and the potential for the function returning decreases as more and more brain cells die. Hence, it is imperative that the therapy indicated in response to the brain injury be executed as soon as possible after the brain injury occurs to minimize such deleterious effects.
An interesting phenomena has been observed by those who study brain injury relating to the brain cell survival rate as a function of time when brain temperature is reduced. In particular, drowning victims in exceptionally cold water have in some cases been submerged and deprived of oxygen for tens of minutes. While such a time period would ordinarily cause such extensive brain cell loss that significant brain function loss would occur, it has been observed that brain function has in many cases been restored completely, or nearly completely. Based on these observations, it has been determined that by cooling the patient's head, an effect similar to “slowing down the clock” can be achieved. Accordingly, a need exists for extending this observed benefit from accidental occurrences to intentional use of this effect in the beneficial treatment of brain injury, and particularly stroke and head trauma.